ISO 17190-8:2020

Overview

ISO 17190-8:2020 specifies a laboratory test method for determining the permeability-dependent absorption under pressure (PDAUP) of polyacrylate superabsorbent powders used in urine-absorbing aids for incontinence. The method uses a gravimetric measurement of saline (0.9 % NaCl) uptake under a defined pressure to evaluate how the permeability of the swollen gel layer controls fluid uptake under constrained conditions.

Key topics and technical requirements

• Scope: Measures PDAUP where permeability is a significant controlling factor in absorption behavior.
• Principle: A known mass of superabsorbent powder (test portion) is placed in a cylinder with a filtered base, compressed by a piston/weight to apply a constant pressure, and allowed to absorb saline for 60 minutes. The absorbed mass is determined gravimetrically.
• Reagents and test fluid: 0.9 % sodium chloride solution prepared with laboratory-grade water (ISO 3696 grade 3); conductivity and temperature control recommended.
• Apparatus: PMMA (or equivalent) cylinder with mesh screen, PTFE piston and calibrated piston weight to give the specified pressure (~4 805 Pa; approx. 49 g/cm² or 0.7 psi), ceramic filter plate, Petri dish/tray, precise analytical balances, timer and filter paper.
• Conditioning and environment: Samples conditioned to laboratory atmosphere (preferred (23 ± 2) °C and (45 ± 15) % RH) per ISO 187.
• Sampling and safety: Instructions for homogenizing powder and checking for lumps; warning about respirable dust (guideline exposure ~0.05 mg/m³) and recommended dust-control precautions.
• Procedure essentials: Even bed formation, prevention of gel blocking, refill of saline to maintain level, 60-minute absorption time, careful removal to avoid liquid carry-over, and specified calculations and reporting.

Applications and users

ISO 17190-8:2020 is useful for:

• Manufacturers of incontinence products and absorbent cores assessing superabsorbent polymer (SAP) performance under pressure.
• Quality control and test laboratories performing absorbency under pressure and supplier qualification.
• R&D teams comparing SAP formulations where permeability of the swollen gel layer affects real-world performance (e.g., under body load or layered structures).
• Regulatory or procurement specialists requiring standardized test data for product specifications or claims.

Practical applications include product development, comparative material selection, batch acceptance testing, and establishing design limits for urine-absorbing aids.

Related standards

• ISO 17190 series (other parts for polyacrylate superabsorbent powders)
• ISO 17190-7 (related absorbency methods referenced)
• ISO 187 (conditioning atmosphere)
• ISO 3696 (water for analytical use)
• ISO 4793 (ceramic filter plate porosity)

Keywords: ISO 17190-8:2020, PDAUP, polyacrylate superabsorbent powders, gravimetric measurement, saline solution, absorbency under pressure, incontinence products, superabsorbent polymer test method.